Apparatus for molding rubber articles



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APPARATUS FORMOLDING RUBBER ARTICLES Filed May 6, 1950 2 Sheets-Sheet l @nvm/stoms M March 10, 1931. H. wxLLsHAw ET Al. n 1,735,917

APPARATUS FOR MOLDING RUBBER ARTICLES Filed May 6, 1950 2 Sheets-Sheet 2 @n mattez/1401345 @Qd-M Patented Mar. 10, 1931 Y narran srnrns entrenar erricr: g

HARRY "WIIJILSHAVV',l OF WYADE GREEN, AND SYDNEY NEVILLE GOODHALL, O MARSTEN GREEN, ENGLAND, ASSIGNORS TO'DUNLOP TIRE AND RUBBER CORPOBAJ Tron, AN AMEnIcAN conronATIoN APPARATUS knon MOLDING RUBBER ARTICLES Application filed Mayy 6, 1930, Serial No. 450,082, and in Great Britain May 5, 1929.

This vinvention relates to molding of hollow articles particularly of playing balls, for example, tennis balls, and more particularly to molding apparatus comprising individually hinged heating chambers of the pot or watch case type.

*Objectsof our invention are to provide a compact and conveniently operated molding apparatus of the above type; to provide ef- 'ective and readily operated closing, clamping and opening means for apparatus of the above type, and to provide apparatus of the above type that may be operated in batteries or may be operated by automatic mecha-A ,5 nlsms. Y.

With these and other objects in view which will more fully appear from the following description, the invention comprises the apparatus described in the following` specification and claims. i 1 Y The various features of the invention are illustrated in the accompanying drawings, in .whichl l Fig. l is a side'view, parts being broken Aaway to show the interior construction, of a preferred form 'of apparatus embodying` our present invention. f Y

Fig. 2 is a vertical section of therapparatus taken on the line 2-2 of Fig. l.

Fig. 3 is a planview ofthe apparatus, and Figs. l and 5 are sectional views of the apparatustalren on the line lr-a oi F ig. 3, but showing themodiiied forms of embodiment.

Inl our invention the hollow articles, such .v

g5 as tennisballs, are molded in apparatus come prising a fixed heated chamber and a movable heated chamber, the movable heated cham# ber being hinged relatively to the tiredY cham-` ber and-adapted to swing freely to and from said iix'ed chamber; Thechambersare preferabiy arranged horizontally wih thelix'ed chamber underneathy and kthe -hinged :chamber so arranged vthat it may be lifted on its hinge to an upright position, or lowered to rest upon the lower chamber. These chambers are preferablyv of annular -orm having a number ot' molds, sin being shown in the ac'- companying drawings, formed of comple-j mentary parts, one part being iixed or formed in the upper chamber and the other partbe ing fixed or 'formed in the lower chamber'. When the upper chamber is inposition resting on the lower chamber it is locked and clamped against'the latter by means of a locking and compressing arrangement that exerts a forced multiplying action, preferably by means of an eccentric toggle arrangement.` rihis locking or toggle mechanism, however, exerts a resilient or springing action in locking the two chambers to ensure a tight locking with,- out the necessity of making -adjustments )for unevenness. Wvhen the clamping and locking mechanism i'smoved rcversely to unlocking position it also exerts an opening force on the upper chamber. f

Referring to Figs. l, 2 and 3 of the accompanying drawings, the invention is shown as embodied in apparatus comprising two superposed steam chests l and 2, the lower chest l being disposed horizontally or substantially so, and fixed toa suitable `frame 3, and the upper chest 2 being hinged at 4 inrelation to the lower chest and provided with a. suitable balance weight 5. riChe frame 3 is adap'ted'to be fined to a table orother support to position it at a convenient working height. i

The chests carry` the mold members and,

as shown particularly in Fig. l, the latter are separate hemispherical shells 6" let into appropriately shaped depressions '7 in said chests. may be provided with the required molding surfaces. i

Alternately, thek chests themselves The apparatus shown invFigsfl, 2 and 3 'A is designed to treat siX balls, each chest car-y rying siX shells each of which mates with a complementary shell as shown in Figs.V l and 2 to give the required six molding cavities as shownin Fig. 3. l v

, Steam is circulated through the chests via suitable piping; the steam for the top chest entering by the pipe 8 and leaving by the pipe 9, passes through the trunnion or hinge 1() for said chest, as shown particularly in Fig. 3. l/Vater may' also be circulated through the system for cooling purposes.

As shown in the drawings theV chests 1 and 2 are in the form of annular rings having a central bore or aperture ll-other forms providing such a central aperture may also be used.

This allows the required pressure to be eX- erted between the chests for closing and opening by a centrally disposed clamp or the like, thus superseding the usual tire-pot arrangement utilisa a plurality of clamps spaced around the outer periphery of the chests.

As shown in Figs. 1, 2 and 3 of the drawings, pressure is exerted by eccentric gear, the clamp comprising a pivotal claw lever 12 adapted to engage a bridge piece 13 extending across the bore 11, cf the hinging chest 2. Said lever 12 is pivotally mounted, as shown .at lll, on a shaft 15 which is eccentrically mounted as shown at 16 in bearings 17 each side of the frame 3. Pressure is applied'by rotating said shaft, by means of a handle 18 attached to it, thereby to displace said lever by the eccentric throw of said shaft.

The pressure to keep the chests closed is preferably applied through a spring medium-in this way the molding pressure is characterized in a desirable resiliency, any slight misalignment or separation, or tendency thereto of the contacting chests or molds vis allowed for, and the necessity for small adjustments of the eccentric as to take up wear is obviated. As shown in the drawings, the required resiliency is provided by the shaft V15 which carried the claw lever 12, said shaft being so designed that it will spring or whip slightly between its bearings 17 when the toggle pressure is applied.

The claw lever may, as shown at 19, Fig'. A1, be spring loaded normally to bear toward and engage the bridge piece 13 and the handle 18 may in the reverse or opening movel nient be used to pass said claw lever clear of the bridge piece so as to give the hing-ing chest a clear path both in opening` and closing. As shown in Figs. 1 and 2 the arrangement comprises a pair of members 2O fixed to the shaft 15, which members are adapted to co-act as hereinafter set out with pegs 21 fixed to the lever 12.

In the lower chest 1 there are provided two or more spring loaded plungers-22 vwhich are arranged vertically so that their ends project above the surfaceof said lower chests as shown in 1. These plungers act as a cushion or brake to prevent the top chest being fiung too violently against the lower chest in closing, with consequent damage to the chests of the mating parts of the molds. Said held at an angle to the lower by its balance A weight 5, and the handle 18 is in a substantially vertical position.. Balls are new placed in the cavities in the'lower chest and the top chest is swung downward onto said lower chest by the handle 25. To 'allow of this last movement the pressurehandle 18 is meantime held manually pressed away from the operator slightly so thatgthe members 20 contact the pegs 21and so keep the claw lever 12 held back out of the way otV the top chest as it descends. The chests being together, the handle 18 is now pulled toward the operator and the claw lever 12' thereupon moves under the influence of its spring to engage the bridge piece 13. Continued operation of the handle 18 in the same direction operates the eccentric gear as aforesaid to exert the required pressure between the chests, the eccentric shaft 15 passing a little over dead center to maintain the pressure. Then the apparatus is left until treatment of the balls is complete. Then the handle 18 is moved in the reverse direction, that is, away from the operator. so that the eccentricl gear operates to lift the clamp and so effect initial opening or brealing the lower face of the claw contacting the under side ofthe bridge piece, and so forcing the chests slightly apart against the adhesion of the balls tothe molding cavities. Continued movement of the handle 18 in the same direction causesl the members20V to contact the pegs 21and so force the claw lever out of engagement with the bridge piece 13. rIhe upper chest is then free to be swung manually fully clear-of the lower chest by the handle 25, to allow of the removal of the finished balls. f Y

Instead of the clamp comprisingv eccentric gear as described,'alternatively it may comprise a swing bolt 26, Figs. s and 5. of which the free end'27 engages a slot in the bridge piece 13, the required pressure being exerted either bya wing nut 28, as in Fig. Li, or by a cam clamp 29 as in Fig. 5. Y

Instead of utilizing the spring or whip in the shaft k15 to provide the desired resiliency, we' may use a separate spring, or alternatively, we may dispense with springing entirely. The first alternative is exemplified in We may use a plurality, either disposed in the bore of the chestsor alternatively about their outer periphery. i

The apparatus may be controlled automatically-in one such scheme closing of the apparatus starts a timing means which, after a predetermined time, operates devices to shut oil the steam and Hood the chests with water and, it desired, open the apparatus. A signal may also be used to indicate that the treatment is over and we may also use a graphic device to keep a record of the treatment.V

Suitable arrangements for this are shown in our previous British Patent No. 303,075.

And linally, instead'of being used individually the apparatus may be used in batteries, the units of which may be operated by a common operating means.` ln one eXample, which also providesy an automatic con trol alternative to or auxiliary to that set out in the nent preceding paragraph, aseries oit units are arranged side by side and parallel to them is a driven shaft. Adjacent each unit this shaft carries or operates a cam or cams or the lile adapted to effect at the proper time and in the required sequence, the various movements which Would otherwise be carried out manually, for eirample, opening and closingthe apparatus, and again operating the cocks for flooding ythe chestsV with water, draining said Water trom the chests and admitting steam in its place. rllhe cams are set as betweenrespective units so that said units are operated to suit the Vrate at which the operator or operators can deal with the balls.

Having now described our invention, what we claim is l. Apparatus for molding articles of the type described comprising a pair of heated annular chambers having complementary 't mold portions movable to and from each other, pressure applying means for pressing said chambers together comprising a spindle rotatable inaneccentric bearing, a lever pivoted on said spindle having its free end movable to engage a part oii the other of said chambers whereby, when so engaged, said chamber is drawn toward said lirst chamber as said spindle is rotated in one direction,

' a spring loaded normally to press said lever toward and into engagement with a part on said second chamber, and means actuated by said shaft to disengage said lever trom said part of said chamberv upon a reverse movement of said shaft.

2. Apparatus for molding articles of the type described comprising a pair of heated annular chambers having complementary mold'portions movable to 'and from each other, nressureapplying means for pressing said chamber together comprising a spindle 'rotatable in eccentric, spaced, bearings and capable of being sprung between said bearings, a lever pivotedon said spindle having 

